Just three days after the last release, Apple has made the ninth beta of iOS 11, and tvOS available for developers to test —suggesting a release is imminent in conjunction with new products that need the operating systems to function.

The most notable changes in iOS 11 overall are back-end enhancements and an improved voice for Siri, plus Apple Pay and Photos services enhancements. The Do Not Disturb While Driving feature was introduced during the second beta. The ninth beta of iOS 11 has build number 15A5370a, with the previous holding number 15A5368a —a very small increment since Monday's update

tvOS 11

Apple continues to have very sparse developer notes for tvOS. The previous tvOS build was numbered 15J5374a, and the current has been incremented to 15J5378a.

Earlier on Thursday, Apple declared that its next release event is on September 12. All four of Apple's operating systems in testing are expected to be released on or around the release event, with the "iPhone 8," "iPhone 7s," and "iPhone 7s Plus" likely debuting as well.